Treatments and drugs

Treatment for inherited long QT syndrome can involve medications, medical devices, surgery or lifestyle changes. The goal of treatment is either to prevent the long QT heart from ever beating out of control or to prevent sudden death. Your doctor will discuss with you the most appropriate treatment options for your condition based on your symptoms, your type of long QT syndrome, and your risk of fainting or sudden cardiac arrest.

For acquired long QT syndrome, treating the cause of the condition may eliminate it. Doctors will also treat heart rhythm disorders (arrhythmias) as needed.

If acquired long QT syndrome is due to certain medications, your doctor may recommend that you stop taking the medication causing the condition and switch medications in order to treat the condition. Some people might need additional treatment.

Medications

Medications used to treat long QT syndrome may include:

Beta blockers. Examples of these heart drugs include nadolol (Corgard) and propranolol (Inderal LA, Innopran XL). These drugs slow the heart rate and make the dangerous rhythm associated with long QT syndrome less likely. Beta blockers work by blunting the way a long QT syndrome-affected heart reacts to adrenaline, as it can beat faster in times of stress, fear or exertion.

Mexiletine. In people with a form of long QT syndrome called LQT3, taking this anti-arrhythmic drug in combination with beta blockers might help shorten the QT interval.

Potassium. Potassium is a mineral derived from your diet that's important for the health of your heart's electrical system. For certain forms of long QT syndrome, potassium supplements might improve the heart's recharging system.

Fish oil. Supplementation with heart-healthy fish oil (omega-3 fatty acid) or eating fish high in omega-3 fatty acids might help decrease the risk of abnormal heart rhythms. Consult your doctor before starting fish oil or any other supplements or medications.

Your doctor might suggest treatment for long QT syndrome even if you don't experience frequent signs or symptoms of the condition.

If you do need treatment, take the medications your doctor prescribes for long QT syndrome as directed. While medications won't cure the condition, they provide some protection against potentially fatal disruptions of your heart rhythm. You might need to take a medication such as a beta blocker indefinitely.

Medical devices and surgical procedures

A pacemaker or implantable cardioverter-defibrillator (ICD). These devices, which are implanted under the skin of your chest, can stop a potentially fatal arrhythmia.

An ICD continuously monitors your heartbeat. If it detects an abnormal heart rhythm, it delivers electrical shocks to reset the heart to a normal heart rhythm.

If a pacemaker detects a heart rate that's abnormal, it emits electric impulses that stimulate your heart to beat at a normal rate.

Left cardiac sympathetic denervation surgery. In this procedure, specific nerves in your chest are surgically removed. These nerves are part of the body's sympathetic nervous system, which controls automatic functions in the body including regulation of heart rhythm. Left cardiac sympathetic denervation surgery significantly reduces the risk of sudden death.

This surgery is generally reserved for people considered at high risk of sudden death, people who don't tolerate their medications or have a fainting spell despite their medications, and people who have an implanted ICD and are experiencing ICD shocks. Left cardiac sympathetic denervation surgery might significantly reduce the frequency of such appropriate ICD shocks.

Lifestyle changes

In addition to medications or surgery, your doctor might recommend lifestyle changes to reduce your chances of a long QT syndrome-related fainting spell or sudden cardiac arrest. These could include:

Avoiding medications that could cause prolonged QT intervals

Staying well-hydrated during illnesses that are causing vomiting or diarrhea

Lowering your temperature if a fever occurs

Reducing loud or startling noises

Staying away from situations that could make you excited or angry

Avoiding strenuous exercise or contact sports, or have a safety plan in place if you'll be continuing competitive sports

Work with your doctor to balance these lifestyle recommendations against the clear, heart-healthy benefits of an active lifestyle. In some circumstances, it might be possible to stay fully active in sports, including competitive sports, after carefully reviewing the risks and benefits with your doctor.

If your symptoms are mild or don't occur very often, your doctor might recommend only simple preventive measures or lifestyle changes for your condition, and he or she might not prescribe any daily medications for you.

Ackerman MJ, et al. HRS/EHRA expert consensus statement on the state of genetic testing for the channelopathies and cardiomyopathies: This document was developed as a partnership between the Heart Rhythm Society (HRS) and the European Heart Rhythm Association (EHRA). Heart Rhythm. 2011;8:1308.

Legal Conditions and Terms

Reprint Permissions

A single copy of these materials may be reprinted for noncommercial personal use only. "Mayo," "Mayo Clinic," "MayoClinic.org," "Mayo Clinic Healthy Living," and the triple-shield Mayo Clinic logo are trademarks of Mayo Foundation for Medical Education and Research.